1. Field of the Invention
The present invention relates to an intake module of an internal-combustion engine.
2. Description of Related Art
In recent years, modularization of functional portions that constitute an inlet system of an internal-combustion engine has been promoted. More specifically, the functional portions such as a surge tank and an intake manifold constituting the inlet system have been formed integrally. By integrating the functional portions constituting the inlet system into a module, the whole module is downsized. The functional portions constituting the inlet system are modularized integrally using resin. Accordingly, reduction in weight of the whole module is achieved.
Recent internal-combustion engines employ exhaust gas recirculation (EGR), whereby exhaust air discharged from the internal-combustion engine is returned to be mixed into intake air, in order to reduce discharged nitrogen oxide and the like. In such an intake module, as described in JP2006-233859A, for example, a return pipe portion through which exhaust air is returned is connected to a surge tank of the intake module.
However, when the returned exhaust air is led into the intake module, the inlet system and an exhaust system need to be connected. Accordingly, complicated treatment needs to be given to piping, so that the whole module is upsized. In the case of an internal-combustion engine for a vehicle, in particular, a space, in which the internal-combustion engine is installed, is severely constrained. Thus, downsizing of the intake module is strongly demanded.